The reply by Cook and comment by Chao demonstrate Kuhn's thesis that different scientists place different values on different components of their common discipline. This fact is demonstrated by first succinctly summarizing Cook's and my original points within the framework of a simple choice model. I then respond to Cook and Chao. I close by offering some suggestions on how the Textbook/LSE debate could be moved forward.

In a recent article, Cook conducted a Kuhnian analysis of the difference between the Textbook and LSE econometric approaches. This paper uses a semantic conception of theories (Suppe 1989) and a finer gradation of the theory of reduction process to clarify the apparent puzzle that exist between the Textbook and LSE approaches to econometrics. The paper demonstrates that a Kuhnian analysis in isolation can be more misleading than realized.

Trygve Haavelmo's 1944 article ‘The Probability Approach in Econometrics’ is considered by most to have provided the foundations for present day econometrics (Morgan, 1990, Chapters 8 and 9). Since Haavelmo (1944), extraordinary advances have been made in econometrics. However, over the last two decades the efficacy and scientific status of econometrics has become questionable. Not surprisingly, the growing discontent with econometrics has been accompanied by a growing interest in econometric methodology.